Diagnostic precision of nanoparticle-enhanced MRI for lymph-node metastases: a meta-analysis

Nanotheranostics in cancer lymph node metastasis: The long road ahead

Lymph node metastasis (LNM) significantly impacts the prognosis of cancer patients. Despite significant advancements in diagnostic techniques and treatment modalities, clinical challenges continue to persist in the realm of LNM. These include difficulties in early diagnosis, limited treatment efficacy, and potential side effects and injuries associated with treatment. Nanotheranostics, a field within nanotechnology, seamlessly integrates diagnostic and therapeutic functionalities. Its primary goal is to provide precise and effective disease diagnosis and treatment simultaneously. The development of nanotheranostics for LNM offers a promising solution for the stratified management of patients with LNM and promotes the advancement of personalized medicine. This review introduces the mechanisms of LNM and challenges in its diagnosis and treatment. Furthermore, it demonstrates the advantages and development potential of nanotheranostics, focuses on the challenges nanotheranostics face in its application, and provides an outlook on future trends. We consider nanotheranostics a promising strategy to improve clinical effectiveness and efficiency as well as the prognosis of cancer patients with LNM.

Nanomedicine for Diagnosis and Treatment of Atherosclerosis

With the changing disease spectrum, atherosclerosis has become increasingly prevalent worldwide and the associated diseases have emerged as the leading cause of death. Due to their fascinating physical, chemical, and biological characteristics, nanomaterials are regarded as a promising tool to tackle enormous challenges in medicine. The emerging discipline of nanomedicine has filled a huge application gap in the atherosclerotic field, ushering a new generation of diagnosis and treatment strategies. Herein, based on the essential pathogenic contributors of atherogenesis, as well as the distinct composition/structural characteristics, synthesis strategies, and surface design of nanoplatforms, the three major application branches (nanodiagnosis, nanotherapy, and nanotheranostic) of nanomedicine in atherosclerosis are elaborated. Then, state-of-art studies containing a sequence of representative and significant achievements are summarized in detail with an emphasis on the intrinsic interaction/relationship between nanomedicines and atherosclerosis. Particularly, attention is paid to the biosafety of nanomedicines, which aims to pave the way for future clinical translation of this burgeoning field. Finally, this comprehensive review is concluded by proposing unresolved key scientific issues and sharing the vision and expectation for the future, fully elucidating the closed loop from atherogenesis to the application paradigm of nanomedicines for advancing the early achievement of clinical applications.

Significance and prognostication of mediastinal lymph node enlargement on chest computed tomography among adult Indigenous Australians

INTRODUCTION

There is a lack of data on chest computed tomography (CT) findings on mediastinal lymph node enlargement (MLE), including normal size threshold of less than 10 or 15 mm for MLE among Indigenous Australians. In this study, we assessed the significance and the applicability of the current guidelines for the threshold for abnormal MLE among adult Indigenous Australians.

METHODS

Patients who underwent chest CT between 2012 and 2020 among those referred to undergo lung function test (spirometry) were assessed for the presence of MLE which were classified as Group A (no measurable nodes), Group B (<10 mm), Group C (≥10 to 14.99 mm) and Group D (≥15 mm).

RESULTS

Of the total 67 patients identified to have MLE, 49 patients had at least two CT scans available for assessment over a median follow-up period of 101.3 weeks (IQR: 62.4, 235.6) and were included in the analysis. Evidence of chronic lung disease was common, with a significant proportion demonstrating either COPD or bronchiectasis and a high proportion with smoking history (93%). During the first CT scan, 34/49 (69%) had >10 mm nodes, of which 12/34 (35%) reduced in size, 22/34 (65%) remained stable, and 3/34 (9%) had malignancy on follow-up.

CONCLUSION

Despite most patients demonstrating the presence of significant MLE with varying size and in most >10 mm, the majority remain stable or benign in nature and only a minor proportion showed evidence of lung malignancy. Further prospective studies are needed in the characterisation of MLE among Indigenous patients.

Functional roles of magnetic nanoparticles for the identification of metastatic lymph nodes in cancer patients

Staging lymph nodes (LN) is crucial in diagnosing and treating cancer metastasis. Biotechnologies for the specific localization of metastatic lymph nodes (MLNs) have attracted significant attention to efficiently define tumor metastases. Bioimaging modalities, particularly magnetic nanoparticles (MNPs) such as iron oxide nanoparticles, have emerged as promising tools in cancer bioimaging, with great potential for use in the preoperative and intraoperative tracking of MLNs. As radiation-free magnetic resonance imaging (MRI) probes, MNPs can serve as alternative MRI contrast agents, offering improved accuracy and biological safety for nodal staging in cancer patients. Although MNPs' application is still in its initial stages, exploring their underlying mechanisms can enhance the sensitivity and multifunctionality of lymph node mapping. This review focuses on the feasibility and current application status of MNPs for imaging metastatic nodules in preclinical and clinical development. Furthermore, exploring novel and promising MNP-based strategies with controllable characteristics could lead to a more precise treatment of metastatic cancer patients.

The translational paradigm of nanobiomaterials: Biological chemistry to modern applications

Recently nanotechnology has evolved as one of the most revolutionary technologies in the world. It has now become a multi-trillion-dollar business that covers the production of physical, chemical, and biological systems at scales ranging from atomic and molecular levels to a wide range of industrial applications, such as electronics, medicine, and cosmetics. Nanobiomaterials synthesis are promising approaches produced from various biological elements be it plants, bacteria, peptides, nucleic acids, etc. Owing to the better biocompatibility and biological approach of synthesis, they have gained immense attention in the biomedical field. Moreover, due to their scaled-down sized property, nanobiomaterials exhibit remarkable features which make them the potential candidate for different domains of tissue engineering, materials science, pharmacology, biosensors, etc. Miscellaneous characterization techniques have been utilized for the characterization of nanobiomaterials. Currently, the commercial transition of nanotechnology from the research level to the industrial level in the form of nano-scaffolds, implants, and biosensors is stimulating the whole biomedical field starting from bio-mimetic nacres to 3D printing, multiple nanofibers like silk fibers functionalizing as drug delivery systems and in cancer therapy. The contribution of single quantum dot nanoparticles in biological tagging typically in the discipline of genomics and proteomics is noteworthy. This review focuses on the diverse emerging applications of Nanobiomaterials and their mechanistic advancements owing to their physiochemical properties leading to the growth of industries on different biomedical measures. Alongside the implementation of such nanobiomaterials in several drug and gene delivery approaches, optical coding, photodynamic cancer therapy, and vapor sensing have been elaborately discussed in this review. Different parameters based on current challenges and future perspectives are also discussed here.

LA-ICP-MS and Immunohistochemical Staining with Lanthanide-Labeled Antibodies to Study the Uptake of CeO2 Nanoparticles by Macrophages in Tissue Sections

Due to the increasing use and production of CeO₂ nanoparticles (NPs), the likelihood of exposure especially via the air rapidly grows. However, the uptake of CeO₂ NPs via the lung and the resulting distribution into various cell types of remote organs are not well understood because classical analytical methods provide limited spatial information. In this study, laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) was combined with immunohistochemical (IHC) staining with lanthanide-labeled antibodies to investigate the distribution of intratracheally instilled CeO₂ NPs from the rat lung to lymph nodes, spleen, and liver after 3 h, 3 days, and 21 days. We selected regions of interest after fast imaging using LA-ICP-MS in low-resolution mode and conducted high-resolution LA-ICP-MS in combination with IHC for cellular localization. The lanthanide labeling, which was largely congruent with conventional fluorescent labeling, allowed us to calculate the association rates of Ce to specific cell types. Major portions of Ce were found to be associated with phagocytic cells in the lung, lymph nodes, spleen, and liver. In the lung, almost 94% of the Ce was co-localized with CD68-positive alveolar macrophages after 21 days. Ce was also detected in the lymph nodes outside macrophages 3 h post instillation but shifted to macrophage-associated locations. In the liver, Ce accumulations associated with Kupffer cells (CD163-positive) were found. Ce-containing populations of metallophilic and marginal zone macrophages (both CD169-positive) as well as red pulp macrophages (CD68-positive) were identified as major targets in the spleen. Overall, high-resolution LA-ICP-MS analysis in combination with IHC staining with lanthanide-labeled antibodies is a suitable tool to quantify and localize Ce associated with specific cell types and to estimate their particle burden under in vivo conditions.

Lymph Nodes Evaluation in Rectal Cancer: Where Do We Stand and Future Perspective

The assessment of nodal involvement in patients with rectal cancer (RC) is fundamental in disease management. Magnetic Resonance Imaging (MRI) is routinely used for local and nodal staging of RC by using morphological criteria. The actual dimensional and morphological criteria for nodal assessment present several limitations in terms of sensitivity and specificity. For these reasons, several different techniques, such as Diffusion Weighted Imaging (DWI), Intravoxel Incoherent Motion (IVIM), Diffusion Kurtosis Imaging (DKI), and Dynamic Contrast Enhancement (DCE) in MRI have been introduced but still not fully validated. Positron Emission Tomography (PET)/CT plays a pivotal role in the assessment of LNs; more recently PET/MRI has been introduced. The advantages and limitations of these imaging modalities will be provided in this narrative review. The second part of the review includes experimental techniques, such as iron-oxide particles (SPIO), and dual-energy CT (DECT). Radiomics analysis is an active field of research, and the evidence about LNs in RC will be discussed. The review also discusses the different recommendations between the European and North American guidelines for the evaluation of LNs in RC, from anatomical considerations to structured reporting.

Vulvar Cancer: 2021 Revised FIGO Staging System and the Role of Imaging

Vulvar cancer is a rare gynecological malignancy. It constitutes 5-8% of all gynecologic neoplasms, and squamous cell carcinoma is the most common variant. This article aims to review the etiopathogenesis revised 2021 International Federation of Gynecology and Obstetrics (FIGO) classification and emphasize imaging in the staging of vulvar cancer. The staging has been regulated by FIGO since 1969 and is subjected to multiple revisions. Previous 2009 FIGO classification is limited by the prognostic capability, which prompted the 2021 revisions and issue of a new FIGO classification. Although vulvar cancer can be visualized clinically, imaging plays a crucial role in the staging of the tumor, assessing the tumor extent, and planning the management. In addition, sentinel lymph node biopsy facilitates the histopathological staging of the draining lymph node, thus enabling early detection of tumor metastases and better survival rates.

Chitosan nanoparticles as a promising tool in nanomedicine with particular emphasis on oncological treatment

The study describes the current state of knowledge on nanotechnology and its utilization in medicine. The focus in this manuscript was on the properties, usage safety, and potentially valuable applications of chitosan-based nanomaterials. Chitosan nanoparticles have high importance in nanomedicine, biomedical engineering, discovery and development of new drugs. The manuscript reviewed the new studies regarding the use of chitosan-based nanoparticles for creating new release systems with improved bioavailability, increased specificity and sensitivity, and reduced pharmacological toxicity of drugs. Nowadays, effective cancer treatment is a global problem, and recent advances in nanomedicine are of great importance. Special attention was put on the application of chitosan nanoparticles in developing new system for anticancer drug delivery. Pre-clinical and clinical studies support the use of chitosan-based nanoparticles in nanomedicine. This manuscript overviews the last progresses regarding the utilization, stability, and bioavailability of drug nanoencapsulation with chitosan and their safety.

New frontiers in esophageal radiology

Esophageal cancer is the sixth most common cause of cancer related mortality worldwide. Advances in treatment have translated into steadily improving survival rates. Accurate preoperative staging of esophageal cancer is imperative in order to provide an accurate prognosis and direct patients to the most appropriate treatment. Current preoperative staging relies on imaging, most commonly endoscopic ultrasound (EUS), computed tomography (CT) and positron emission tomography (PET). A combination of these modalities should be used in preoperative staging, as each has advantages over another. Magnetic resonance imaging (MRI) has always shown promise in its ability to accurately stage esophageal cancer, though it has not been consistently adopted as a common tool for this purpose. Recent research has demonstrated that MRI can become an integral part of esophageal cancer clinical staging. Advances in MR technology that utilize radial sampling allow for shorter, free breathing techniques without degradation of image quality, resulting in improved capability for T and N staging of esophageal cancer. MRI enhanced with superparamagnetic iron oxide (SPIO) and ultrasmall SPIO (USPIO) nanoparticles has been shown to be useful for the detection of metastatic disease in lymph nodes. This article will review the current evidence in the role that imaging plays in staging esophageal cancer.

Clinical characteristics and oncologic outcomes in patients with preoperative clinical T3 and T4 colon cancer who were staged as pathologic T3

Purpose

Clinically suspected T4 stage colon cancer from a preoperative exam is often diagnosed as T3 stage colon cancer pathologically after surgery, raising concerns about understaging. The aims of this study were to compare the survival of clinical T3 and T4 colon cancer patients who had received a pathologic T3 stage diagnosis postoperatively.

Methods

Patients who were diagnosed with pathologic T3 stage colon cancer postoperatively were reviewed. Patients with clinically suspected T3 or T4 stage cancer on preoperative exam were enrolled in the study. We compared patient demographics and survival of the cT3 and cT4 groups.

Results

Out of the 536 patients with pT3 colon cancer, 503 patients were cT3 (93.8%) and 33 patients were cT4 (6.2%) preoperatively. The most common reason for suspected clinical T4 stage cancer was free perforation (78.8%). There were no statistically significant differences between the 5-year overall survival and the total 5-year disease-free survival (DFS) between the cT3 and cT4 groups; however, local recurrence was significantly higher in the cT4 group (local 5-year DFS: 98.6% vs. 84.0%, P < 0.001). Multivariate analysis showed cT stage was associated with local recurrence, but the association was not statistically significant (P = 0.056).

Conclusion

Preoperative clinically suspected T4 stage colon cancer showed inferior local recurrence despite a postoperative pathologic diagnosis of T3 stage cancer. It is necessary to address the shortcomings of pathologic exams in the matter of the understaging of T4 colon cancer, and to reinforce the treatment for local control in patients with cT4 colon cancer.

Effect of understaging on local recurrence of rectal cancer

Background and Objectives

Magnetic resonance imaging of the pelvis has a limited accuracy to detect positive lymph nodes but does dictate neoadjuvant treatment in rectal cancer. This study aimed to investigate preoperative lymph node understaging and its effects on postoperative local recurrence rate.

Methods

Patients were selected from a retrospective cross‐sectional snapshot study. Patients with emergency surgery, cM1 disease, or unknown cN‐ or (y)pN category were excluded. Clinical and pathologic N‐categories were compared and the impact on local recurrence was determined by multivariable analysis.

Results

Out of 1548 included patients, 233 had preoperatively underestimated lymph node staging based on (y)pN category. Out of the 695 patients staged cN0, 168 (24%) had positive lymph nodes at pathology, and out of the 594 patients staged cN1, 65 (11%) were (y)pN2. Overall 3‐year local recurrence rate was 5%. Clinical N‐category was not associated with local recurrence when corrected for pT‐category, neoadjuvant therapy, and resection margin, neither in patients with (y)pN1 (hazard ratio [HR]: 1.67 (95% confidence interval [CI]: 0.68‐4.12) P = .263) nor (y)pN2‐category (HR: 1.91 95% CI: [0.75‐4.84], P = .175).

Conclusion

Preoperative understaging of nodal status in rectal cancer is not uncommon. No significant effect on local recurrence or overall survival rates were found in the present study.

Data from a terminated study on iron oxide nanoparticle magnetic resonance imaging for head and neck tumors

Node positive head and neck squamous cell carcinomas (HNSCCs) patients exhibit worse outcomes in terms of regional neck control, risk for distant metastases and overall survival. Smaller non-palpable lymph nodes may be inflammatory or may harbor clinically occult metastases, a characterization that can be challenging to make using routine imaging modalities. Ferumoxytol has been previously investigated as an intra-tumoral contrast agent for magnetic resonance imaging (MRI) for intracranial malignancies and lymph node agent in prostate cancer. Hence, our group was motivated to carry out a prospective feasibility study to assess the feasibility of ferumoxytol dynamic contrast enhanced (DCE)-weighted MRI relative to that of gadolinium-based DCE-MRI for nodal and primary tumor imaging in patients with biopsy-proven node-positive HNSCC or melanoma. Although this institutional review board (IRB)-approved study was prematurely terminated because of an FDA black box warning, the investigators sought to curate and publish this unique dataset of matched clinical, and anatomical and DCE MRI data for the enrolled five patients to be available for scientists interested in molecular imaging.

Measurement(s)	imaging assay • head and neck squamous cell carcinoma
Technology Type(s)	magnetic resonance imaging
Factor Type(s)	contrast agent
Sample Characteristic - Organism	Homo sapiens

Machine-accessible metadata file describing the reported data: 10.6084/m9.figshare.11409516

Nanoscale systems for local drug delivery

Many diseases and conditions affect a relatively localized area of the body. They can be treated either by direct deposition of drug in the target area, or by giving the drug systemically. Here we review nanoparticle-based approaches to achieving both. We highlight advantages and disadvantages that nanoscale solutions have for locally administered therapies, with emphasis on the former. We discuss strategies to enable systemically delivered nanoparticles to deliver their payloads at specific locations in the body, including triggering (local and remote) and targeting.

[Rational staging and follow-up of colorectal cancer : Do guidelines provide further help?]

CLINICAL/METHODICAL ISSUE

Colorectal cancer is one of the most common malignant tumors. Preoperative imaging is crucial in rectal cancer as patients can only receive optimal treatment when accurate staging is performed. The N‑staging is often difficult with the available options and must be called into question as a staging parameter.

STANDARD RADIOLOGICAL METHODS

Endoscopic ultrasound (EUS) and magnetic resonance imaging (MRI) are particularly suitable for local staging. Multiparametric MRI with diffusion imaging is indispensable for tumor follow-up.

METHODICAL INNOVATIONS

The assessment of infiltration of the mesorectal fascia is best accomplished using high-resolution MRI. In addition, extramural vascular infiltration (EMVI) has become established as another important prognostic factor. After neoadjuvant therapy and restaging of locally advanced rectal cancer, the identification and validation of prognostically relevant image parameters are prioritized. Multiparametric MRI of the rectum including diffusion imaging as well as the application of radiological and pathological scores (MR-TRG) are becoming increasingly more important in this context.

ASSESSMENT

For the radiologist it is important to become familiar with indicators of the resectability of rectal cancer and to be able to reliably read prognostically relevant imaging parameters in the tumor follow-up.

PRACTICAL RECOMMENDATIONS

For the practical application, the establishment of a fixed MRI protocol is essential. In addition to a guideline-compliant TNM classification, the radiologist must provide the clinician with information on infiltration of the mesorectal fascia and extramural vascular infiltration. The MR-TRGs are becoming increasingly more important in tumor follow-up.

Synthesis and Enhanced Cellular Uptake In Vitro of Anti-HER2 Multifunctional Gold Nanoparticles

Nanoparticle carriers offer the possibility of enhanced delivery of therapeutic payloads in tumor tissues due to tumor-selective accumulation through the enhanced permeability and retention effect (EPR). Gold nanoparticles (AuNP), in particular, possess highly appealing features for development as nanomedicines, such as biocompatibility, tunable optical properties and a remarkable ease of surface functionalization. Taking advantage of the latter, several strategies have been designed to increase treatment specificity of gold nanocarriers by attaching monoclonal antibodies on the surface, as a way to promote selective interactions with the targeted cells—an approach referred to as active-targeting. Here, we describe the synthesis of spherical gold nanoparticles surface-functionalized with an anti-HER2 antibody-drug conjugate (ADC) as an active targeting agent that carries a cytotoxic payload. In addition, we enhanced the intracellular delivery properties of the carrier by attaching a cell penetrating peptide to the active-targeted nanoparticles. We demonstrate that the antibody retains high receptor-affinity after the structural modifications performed for drug-conjugation and nanoparticle attachment. Furthermore, we show that antibody attachment increases cellular uptake in HER2 amplified cell lines selectively, and incorporation of the cell penetrating peptide leads to a further increase in cellular internalization. Nanoparticle-bound antibody-drug conjugates retain high antimitotic potency, which could contribute to a higher therapeutic index in high EPR tumors.

Synthesis and characterisation of iron oxide nanoparticles conjugated with epidermal growth factor receptor (EGFR) monoclonal antibody as MRI contrast agent for cancer detection

The aim of this study is to synthesise superparamagnetic iron oxide nanoparticles conjugated with anti-epidermal growth factor receptor monoclonal antibody (ANTI-EGFR-SPION) and investigate its physicochemical characterisation and biocompatibility as a targeted magnetic resonance imaging (MRI) contrast agent for the EGFR-specific detection in EGFR expressing tumour cells. These particles employed biocompatible polymers, poly(D,L-lactide-co-glycolide) (PLGA) and polyethylene glycol aldehyde (PEG-aldehyde), to increase the half-life of particles in circulation and reduce their side effects. The Fe₃O₄-loaded PLGA-PEG-aldehyde nanoparticles were prepared by a modified water-in-oil-in-water double emulsion method. The EGFR antibody was conjugated to the surface of SPIONs using the aldehyde-amine reaction. Synthesised conjugates (nanoprobes) were characterised using Fourier transform infrared spectrophotometry, dynamic light scattering, transmission electron microscopy images, and vibrating-sample magnetometery, and the results showed that the conjugation was successful. The mean diameter of nanoprobes was about 25 nm. These nanoprobes exhibited excellent water-solubility, stability, and biocompatibility. Meanwhile, MR susceptibility test proved that synthesised nanoprobes can be managed for negative contrast enhancement. The results of this study suggested the potential use of these nanoprobes for non-invasive molecular MRI in EGFR detection in the future.

Heterogeneous Enhancement Pattern in DCE-MRI Reveals the Morphology of Normal Lymph Nodes: An Experimental Study

Purpose

To investigate the heterogeneous enhancement pattern in normal lymph nodes of healthy mice by different albumin-binding contrast agents.

Methods

The enhancement of normal lymph nodes was assessed in mice by dynamic contrast-enhanced MRI (DCE-MRI) after the administration of two contrast agents characterized by different albumin-binding properties: gadopentetate dimeglumine (Gd-DTPA) and gadobenate dimeglumine (Gd-BOPTA). To take into account potential heterogeneities of the contrast uptake in the lymph nodes, k-means cluster analysis was performed on DCE-MRI data. Cluster spatial distribution was visually assessed. Statistical comparison among clusters and contrast agents was performed on semiquantitative parameters (AUC, wash-in rate, and wash-out rate) and on the relative size of the segmented clusters.

Results

Cluster analysis of DCE-MRI data revealed at least two main clusters, localized in the outer portion and in the inner portion of each lymph node. With both contrast agents, AUC (p < 0.01) and wash-in (p < 0.05) rates were greater in the inner cluster, which also showed a steeper wash-out rate than the outer cluster (Gd-BOPTA, p < 0.01; Gd-DTPA, p=0.056). The size of the outer cluster was greater than that of the inner cluster by Gd-DTPA (p < 0.05) and Gd-BOPTA (p < 0.01). The enhancement pattern of Gd-DTPA was not significantly different from the enhancement pattern of Gd-BOPTA.

Conclusion

DCE-MRI in normal lymph nodes shows a characteristic heterogeneous pattern, discriminating the periphery and the central portion of the lymph nodes. Such a pattern deserves to be investigated as a diagnostic marker for lymph node staging.

Imaging vulnerable plaques by targeting inflammation in atherosclerosis using fluorescent-labeled dual-ligand microparticles of iron oxide and magnetic resonance imaging

OBJECTIVE

Identification of patients with high-risk asymptomatic carotid plaques remains an elusive but essential step in stroke prevention. Inflammation is a key process in plaque destabilization and a prelude to clinical sequelae. There are currently no clinical imaging tools to assess the inflammatory activity within plaques. This study characterized inflammation in atherosclerosis using dual-targeted microparticles of iron oxide (DT-MPIO) as a magnetic resonance imaging (MRI) probe.

METHODS

DT-MPIO were used to detect and characterize inflammatory markers, vascular cell adhesion molecule 1 (VCAM-1). and P-selectin on (1) tumor necrosis factor-α-treated cells by immunocytochemistry and (2) aortic root plaques of apolipoprotein-E deficient mice by in vivo MRI. Furthermore, apolipoprotein E-deficient mice with focal carotid plaques of different phenotypes were developed by means of periarterial cuff placement to allow in vivo molecular MRI using these probes. The association between biomarkers and the magnetic resonance signal in different contrast groups was assessed longitudinally in these models.

RESULTS

Immunocytochemistry confirmed specificity and efficacy of DT-MPIO to VCAM-1 and P-selectin. Using this in vivo molecular MRI strategy, we demonstrated (1) the DT-MPIO-induced magnetic resonance signal tracked with VCAM-1 (r = 0.69; P = .014), P-selectin (r = 0.65; P = .022), and macrophage content (r = 0.59; P = .045) within aortic root plaques and (2) high-risk inflamed plaques were distinguished from noninflamed plaques in the murine carotid artery within a practical clinical imaging time frame.

CONCLUSIONS

These molecular MRI probes constitute a novel imaging tool for in vivo characterization of plaque vulnerability and inflammatory activity in atherosclerosis. Further development and translation into the clinical arena will facilitate more accurate risk stratification in carotid atherosclerotic disease in the future.

PET and CT features differentiating infectious/inflammatory from malignant mediastinal lymphadenopathy: A correlated study with endobronchial ultrasound-guided transbronchial needle aspiration

Purpose:

To explore the advantages of differentiating inflammatory from malignant thoracic lymph nodes by integrating their features on positron emission tomography (PET) and computed tomography (CT).

Material and method:

Following institutional review board approval, PET and CT parameters of thoracic lymph nodes were examined based on their pathologic diagnosis via endobronchial ultrasound-guided transbronchial needle aspiration. The standardized uptake value (SUV) of PET and CT findings of the long- and short-axis diameters, axial short to long diameter ratios (S/L), and measured nodal CT values of the lymph nodes were compared and analyzed statistically.

Results:

A total of 124 lymph nodes from 70 patients were studied. The inflammatory and malignant lymph nodes differed significantly in their SUV (P = 0.008), short-axis diameters (SAD, p < 0.001), long-axis diameters (LAD, p = 0.002) and S/L ratios (p < 0.001). They did not differ significantly in non-contrast enhanced CT values (p = 0.304). The sensitivities, specificities, positive predictive values, negative predictive values, diagnostic accuracies and diagnostic odds ratios (DOR) were: 1) elevated SUV alone - 95.31% (61/64), 20% (12/60), 55.96% (61/109), 80% (12/15), 58.87% (73/124), and 5; 2) combined SUV + SAD - 89.06%, 53.33%, 67.06%, 82.05%, 71.77%, and 9.31; 3) combined SUV + S/L ratio - 87.5%, 93.33%, 93.33%, 87.5%, 90.32%, and 98, respectively.

Conclusion:

Increased SUV, SAD, LAD, and S/L ratio are accurate PET/CT parameters to characterize inflammatory or malignant lymph nodes. SUV has high sensitivity but low specificity, low positive and negative predictive values, and low DOR. The SUV + SAD and SUV + S/L ratios have higher specificity, positive and negative predictive values, diagnostic accuracy and DOR.

Accuracy of Preoperative Local Staging of Primary Colorectal Cancer by Using Computed Tomography: Reappraisal Based on Data Collected at a Highly Organized Cancer Center

Purpose

In patients with colorectal cancer, preoperative staging using various imaging technologies is important for establishing the treatment plan and predicting the prognosis. Although computed tomography (CT) has been used most widely, the versatility of CT accuracy was primarily because of the lack of specialization. In this study, we aimed to identify whether any advancement in abdominal CT accuracy in the prediction of local staging has occurred.

Methods

Between December 2014 and November 2015, patients with colorectal cancer were retrospectively enrolled. All CT findings were retrospectively reported. A total of 285 patients were included, and their retrospectively collected data were retrospectively reviewed, focusing on a comparison between preoperative and postoperative staging.

Results

The overall prediction accuracy of the T stage was 55.1%, with overstaging occurring in 63 (22.1%) and understaging in 65 patients (22.8%). The sensitivity and specificity were 90.0% and 68.4%, respectively. The overall prediction accuracy of the N stage was 54.7%, with overstaging occurring in 89 (31.2%) and understaging in 40 patients (14.1%). The sensitivity and specificity were 71.9% and 63.2%, respectively. The CT accuracies by pathologic stage were 0%, 62.2%, 25.3%, and 81.2% for stages 0 (Tis N0), I, II, and III, respectively.

Conclusion

CT has good sensitivity for detecting colon cancers with tumor invasion beyond the bowel wall. However, detection of nodal involvement using CT is unreliable. In our opinion, abdominal CT alone has limitations in predicting the local staging of colorectal cancer, and additional technologies, such as CT plus positron emission tomography and/or colonography, will improve its accuracy.

Prediction of lateral pelvic lymph node metastasis from lower rectal cancer using magnetic resonance imaging and risk factors for metastasis: Multicenter study of the Lymph Node Committee of the Japanese Society for Cancer of the Colon and Rectum

PURPOSE

The goal of the study was to examine prediction of lateral pelvic lymph node (LPLN) metastasis from lower rectal cancer using a logistic model including risk factors for LPLN metastasis and magnetic resonance imaging (MRI) clinical LPLN (cLPLN) status, compared to prediction based on MRI alone.

METHODS

The subjects were 272 patients with lower rectal cancer who underwent MRI prior to mesorectal excision combined with LPLN dissection (LPLD) at six institutes. No patients received neoadjuvant therapy. Prediction models for right and left pathological LPLN (pLPLN) metastasis were developed using cLPLN status, histopathological grade, and perirectal lymph node (PRLN) status. For evaluation, data for patients with left LPLD were substituted into the right-side equation and vice versa.

RESULTS

Left LPLN metastasis was predicted using the right-side model with accuracy of 86.5%, sensitivity 56.4%, specificity 92.7%, positive predictive value (PPV) 61.1%, and negative predictive value (NPV) 91.2%, while these data using MRI cLPLN status alone were 80.4, 76.9, 81.2, 45.5, and 94.5%, respectively. Similarly, right LPLN metastasis was predicted using the left-side equation with accuracy of 83.8%, sensitivity 57.8%, specificity 90.4%, PPV 60.5%, and NPV 89.4%, and the equivalent data using MRI alone were 78.4, 68.9, 80.8, 47.7, and 91.1%, respectively. The AUCs for the right- and left-side equations were significantly higher than the equivalent AUCs for MRI cLPLN status alone.

CONCLUSIONS

A logistic model including risk factors for LPLN metastasis and MRI findings had significantly better performance for prediction of LPLN metastasis compared with a model based on MRI findings alone.

Using Imaging to Predict Treatment Response in Genitourinary Malignancies

CONTEXT

Over the previous2 decades, there have been numerous advancements in the diagnostic evaluation, therapeutic management, and postoperative assessment of genitourinary malignancies.

OBJECTIVE

To present a review of current and novel imaging modalities and their utility in the assessment of therapeutic response in the systemic management of renal, testicular, and prostate cancers.

EVIDENCE ACQUISITION

A PubMed/Medline search of the current published literature inclusive of prospective and retrospective original research, systematic reviews, and meta-analyses was conducted evaluating imaging modalities for renal cell carcinoma, prostate cancer, and testicular cancer. All relevant literature was individually reviewed and summarized to provide a concise description of the currently available imaging modalities and their efficacy in assessing treatment response of the genitourinary malignancies targeted in this review.

EVIDENCE SYNTHESIS

Conventional imaging techniques play a pivotal role in predicting the treatment response of genitourinary malignancies and have, therefore, been incorporated into clinical guidelines. Advancements in imaging technology have led to increased utilization for prognostication of a genitourinary cancer's response to therapy.

CONCLUSIONS

A good understanding of current recommended imaging techniques to evaluate treatment response in genitourinary malignancies is of paramount importance for today's clinician, who faces increasing treatment modalities.

PATIENT SUMMARY

In this review, we summarize available imaging modalities in the evaluation of treatment response in kidney, prostate, or testicular tumors. We believe that a good understanding of current imaging modalities is of paramount importance for healthcare providers treating these cancers.

Potential applications and human biosafety of nanomaterials used in nanomedicine

With the rapid development of nanotechnology, potential applications of nanomaterials in medicine have been widely researched in recent years. Nanomaterials themselves can be used as image agents or therapeutic drugs, and for drug and gene delivery, biological devices, nanoelectronic biosensors or molecular nanotechnology. As the composition, morphology, chemical properties, implant sites as well as potential applications become more and more complex, human biosafety of nanomaterials for clinical use has become a major concern. If nanoparticles accumulate in the human body or interact with the body molecules or chemical components, health risks may also occur. Accordingly, the unique chemical and physical properties, potential applications in medical fields, as well as human biosafety in clinical trials are reviewed in this study. Finally, this article tries to give some suggestions for future work in nanomedicine research. Copyright © 2017 John Wiley & Sons, Ltd.

A comprehensive literatures update of clinical researches of superparamagnetic resonance iron oxide nanoparticles for magnetic resonance imaging

This paper aims to update the clinical researches using superparamagnetic iron oxide (SPIO) nanoparticles as magnetic resonance imaging (MRI) contrast agent published during the past five years. PubMed database was used for literature search, and the search terms were (SPIO OR superparamagnetic iron oxide OR Resovist OR Ferumoxytol OR Ferumoxtran-10) AND (MRI OR magnetic resonance imaging). The literature search results show clinical research on SPIO remains robust, particularly fuelled by the approval of ferumoxytol for intravenously administration. SPIOs have been tested on MR angiography, sentinel lymph node detection, lymph node metastasis evaluation; inflammation evaluation; blood volume measurement; as well as liver imaging. Two experimental SPIOs with unique potentials are also discussed in this review. A curcumin-conjugated SPIO can penetrate brain blood barrier (BBB) and bind to amyloid plaques in Alzheime's disease transgenic mice brain, and thereafter detectable by MRI. Another SPIO was fabricated with a core of Fe3O4 nanoparticle and a shell coating of concentrated hydrophilic polymer brushes and are almost not taken by peripheral macrophages as well as by mononuclear phagocytes and reticuloendothelial system (RES) due to the suppression of non-specific protein binding caused by their stealthy ''brush-afforded'' structure. This SPIO may offer potentials for the applications such as drug targeting and tissue or organ imaging other than liver and lymph nodes.

Magnetic Resonance Imaging of Gynecological Malignancies: Role in Personalized Management

Gynecological malignancies are a leading cause of mortality and morbidity in women and pose a significant health problem around the world. Currently used staging systems for management of gynecological malignancies have unresolved issues, the most important being recommendations on the use of imaging. Although not mandatory as per the International Federation of Gynecology and Obstetrics recommendations, preoperative cross-sectional imaging is strongly recommended for adequate and optimal management of patients with gynecological malignancies. Standardized disease-specific magnetic resonance imaging protocols help assess disease spread accurately and avoid pitfalls. Multiparametric imaging holds promise as a roadmap to personalized management in gynecological malignancies. In this review, we will highlight the role of magnetic resonance imaging in cervical, endometrial, and ovarian carcinomas.

Molecular magnetic resonance imaging discloses endothelial activation after transient ischaemic attack

SEE SUN ET AL DOI101093/AWW306 FOR A SCIENTIFIC COMMENTARY ON THIS ARTICLE: About 20% of patients with ischaemic stroke have a preceding transient ischaemic attack, which is clinically defined as focal neurological symptoms of ischaemic origin resolving spontaneously. Failure to diagnose transient ischaemic attack is a wasted opportunity to prevent recurrent disabling stroke. Unfortunately, diagnosis can be difficult, due to numerous mimics, and to the absence of a specific test. New diagnostic tools are thus needed, in particular for radiologically silent cases, which correspond to the recommended tissue-based definition of transient ischaemic attack. As endothelial activation is a hallmark of cerebrovascular events, we postulated that this may also be true for transient ischaemic attack, and that it would be clinically relevant to develop non-invasive in vivo imaging to detect this endothelial activation. Using transcriptional and immunohistological analyses for adhesion molecules in a mouse model, we identified brain endothelial P-selectin as a potential biomarker for transient ischaemic attack. We thus developed ultra-sensitive molecular magnetic resonance imaging using antibody-based microparticles of iron oxide targeting P-selectin. This highly sensitive imaging strategy unmasked activated endothelial cells after experimental transient ischaemic attack and allowed discriminating transient ischaemic attack from epilepsy and migraine, two important transient ischaemic attack mimics. We provide preclinical evidence that combining conventional magnetic resonance imaging with molecular magnetic resonance imaging targeting P-selectin might aid in the diagnosis of transient ischaemic attack.

Evaluation of 64-Channel Contrast-Enhanced Multi-detector Row Computed Tomography for Preoperative N Staging in cT2-4 Gastric Carcinoma

BACKGROUND

Preoperative N staging is essential for the best treatment planning in patients with gastric carcinoma. The aim of this study was to evaluate the accuracy of preoperative N staging using contrast-enhanced multi-detector row computed tomography (CE-MDCT) in patients with resectable cT2-4 gastric carcinoma.

METHODS

A total of 218 patients who underwent a gastrectomy with D2 lymphadenectomy for previously untreated cT2-4 primary gastric carcinoma were studied. Preoperative N staging was performed according to the 7th (UICC) TNM Staging System using pre-specified criteria on a 64-channel CE-MDCT and was compared with postoperative pathologic N staging.

RESULTS

In all 218 patients, a distal or total gastrectomy was performed. The overall accuracy of the preoperative N staging was 46.3% (101/218), with the proportion of over- and under-staging being 26.6% (58/218) and 27.1% (59/218), respectively. The sensitivity, specificity, and accuracy for lymph node metastasis (≥pN1) were 79.1% (106/134), 50.0% (42/84), and 67.9% (148/218), respectively. The sensitivity, specificity, and accuracy for multiple lymph node metastases (≥pN2) were 80.2% (73/91), 68.5% (87/127), and 73.4% (160/218), respectively. Multivariate analyses showed that macroscopic type 2 and ≥6 cm-sized tumors were associated with preoperative over-N staging, while macroscopic type 1/3 tumors were associated with under-N staging.

CONCLUSION

Preoperative N staging with pinpoint accuracy is difficult. However, CE-MDCT offers a reasonably high sensitivity and specificity for ≥pN2 and may be useful for selecting candidates for neoadjuvant therapies. The macroscopic type and size of the primary tumor may affect the accuracy of preoperative N staging.

The Diagnostic Value of MR Imaging in Determining the Lymph Node Status of Patients with Non-Small Cell Lung Cancer: A Meta-Analysis

Purpose To summarize existing evidence of thoracic magnetic resonance (MR) imaging in determining the nodal status of non-small cell lung cancer (NSCLC) with the aim of elucidating its diagnostic value on a per-patient basis (eg, in treatment decision making) and a per-node basis (eg, in target volume delineation for radiation therapy), with results of cytologic and/or histologic examination as the reference standard. Materials and Methods A systematic literature search for original diagnostic studies was performed in PubMed, Web of Science, Embase, and MEDLINE. The methodologic quality of each study was evaluated by using the Quality Assessment of Diagnostic Accuracy Studies 2, or QUADAS-2, tool. Hierarchic summary receiver operating characteristic curves were generated to estimate the diagnostic performance of MR imaging. Subgroup analyses, expressed as relative diagnostic odds ratios (DORs) (rDORs), were performed to evaluate whether publication year, methodologic quality, and/or method of evaluation (qualitative [ie, lesion size and/or morphology] vs quantitative [eg, apparent diffusion coefficients in diffusion-weighted images]) affected diagnostic performance. Results Twelve of 2551 initially identified studies were included in this meta-analysis (1122 patients; 4302 lymph nodes). On a per-patient basis, the pooled estimates of MR imaging for sensitivity, specificity, and DOR were 0.87 (95% confidence interval [CI]: 0.78, 0.92), 0.88 (95% CI: 0.77, 0.94), and 48.1 (95% CI: 23.4, 98.9), respectively. On a per-node basis, the respective measures were 0.88 (95% CI: 0.78, 0.94), 0.95 (95% CI: 0.87, 0.98), and 129.5 (95% CI: 49.3, 340.0). Subgroup analyses suggested greater diagnostic performance of quantitative evaluation on both a per-patient and per-node basis (rDOR = 2.76 [95% CI: 0.83, 9.10], P = .09 and rDOR = 7.25 [95% CI: 1.75, 30.09], P = .01, respectively). Conclusion This meta-analysis demonstrated high diagnostic performance of MR imaging in staging hilar and mediastinal lymph nodes in NSCLC on both a per-patient and per-node basis. (©) RSNA, 2016 Online supplemental material is available for this article.

Reporter nanoparticle that monitors its anticancer efficacy in real time

The ability to monitor the efficacy of an anticancer treatment in real time can have a critical effect on the outcome. Currently, clinical readouts of efficacy rely on indirect or anatomic measurements, which occur over prolonged time scales postchemotherapy or postimmunotherapy and may not be concordant with the actual effect. Here we describe the biology-inspired engineering of a simple 2-in-1 reporter nanoparticle that not only delivers a cytotoxic or an immunotherapy payload to the tumor but also reports back on the efficacy in real time. The reporter nanoparticles are engineered from a novel two-staged stimuli-responsive polymeric material with an optimal ratio of an enzyme-cleavable drug or immunotherapy (effector elements) and a drug function-activatable reporter element. The spatiotemporally constrained delivery of the effector and the reporter elements in a single nanoparticle produces maximum signal enhancement due to the availability of the reporter element in the same cell as the drug, thereby effectively capturing the temporal apoptosis process. Using chemotherapy-sensitive and chemotherapy-resistant tumors in vivo, we show that the reporter nanoparticles can provide a real-time noninvasive readout of tumor response to chemotherapy. The reporter nanoparticle can also monitor the efficacy of immune checkpoint inhibition in melanoma. The self-reporting capability, for the first time to our knowledge, captures an anticancer nanoparticle in action in vivo.

Hybrid Nanomaterials Based on Iron Oxide Nanoparticles and Mesoporous Silica Nanoparticles: Overcoming Challenges in Current Cancer Treatments

The current approaches used for the treatment of cancer face some clinical limitations such as induction of severe side effects, multidrug resistance (MDR), and low specificity toward metastatic cancer cells. Hybrid nanomaterials hold a great potential to overcome all these challenges. Among hybrid nanoparticles, those based on mesoporous silica and iron oxide nanoparticles (MSNs and IONPs) have gained a privileged place in the biomedical field because of their outstanding properties. There are many studies demonstrating their effectiveness as drug delivery systems, nanoheaters, and imaging contrast agents. This review summarizes the advances related to the utilization of IONPs and MSNs for reducing side effects, overcoming MDR, and inhibiting metastasis. Furthermore, we give a future perspective of the clinical application of these technologies.

Selection of Lymph Node-Positive Cases Based on Perirectal and Lateral Pelvic Lymph Nodes Using Magnetic Resonance Imaging: Study of the Japanese Society for Cancer of the Colon and Rectum

PURPOSE

To investigate the optimum cutoff for lymph node size to identify cases positive for perirectal lymph node (PRLN) and lateral lymph node (LPLN) metastasis of lower rectal cancer on magnetic resonance imaging (MRI).

METHODS

The subjects were 449 patients who underwent preoperative MRI. Mesorectal excision was performed in all patients (combined with lateral pelvic lymph node [LN] dissection in 324) between 2004 and 2013 at 6 institutes. Cases were classified as cN positive and cN negative on the basis of the short axis of the largest LN being greater than or equal to a cutoff or less than a cutoff, respectively. PRLN and LPLN diagnoses using 5 and 10 mm cutoffs were compared with histologic diagnoses. Of the 449 patients, 55 received preoperative chemoradiotherapy. MRI was only performed after this therapy in all of these patients.

RESULTS

For PRLNs, 5 and 10 mm cutoffs gave area under the curve (AUC) values of 0.6364 and 0.5794, respectively. The 5 mm cutoff gave a significantly higher AUC value (P = 0.0152), with an accuracy of 63.7 %, sensitivity of 72.6 %, and specificity of 54.7 %. For right LPLNs, the respective AUC values were 0.7418 and 0.6326 (P = 0.0034), and the variables (5 mm cutoff) were 77.6, 68.6, and 79.7 %. For left LPLNs, AUC values were 0.7593 and 0.6559, respectively (P = 0.0057), and the variables (5 mm cutoff) were 79.3, 70.8, and 81.0 %.

CONCLUSIONS

Identification of LN-positive cases on the basis of PRLN and LPLN sizes was superior at a short-axis 5 mm cutoff. Size-based diagnosis of LN metastasis is simple and useful, but further investigation is needed to clarify whether it is superior to diagnosis based on morphology, such as shape, border, and signal intensity.

Superparamagnetic iron oxide-enhanced MRI at 3 T for accurate axillary staging in breast cancer

BACKGROUND

The aim of this study was to evaluate whether MRI at 3 T with superparamagnetic iron oxide (SPIO) enhancement is an accurate and useful method for detecting metastases in sentinel nodes identified by CT-lymphography (CT-LG) in patients with breast cancer. The results were compared with those obtained using CT-LG alone and diagnosing metastasis according to size criteria.

METHODS

Patients with clinically node-negative breast cancer were included. Sentinel nodes identified by CT-LG were evaluated prospectively using SPIO-enhanced MRI at 3 T. Sentinel node size was measured on CT-LG, and a node larger than 5 mm in short-axis diameter was considered metastatic. Sentinel nodes localized by CT-LG were removed, and imaging results and histopathological findings were compared.

RESULTS

Sentinel nodes were identified successfully by CT-LG in 69 (99 per cent) of 70 patients. All 19 patients with a finding of metastasis in sentinel nodes at pathology were also shown to have metastases on MRI. Forty-eight of 50 patients with non-metastatic sentinel nodes diagnosed at pathology were classified as having non-metastatic nodes on MRI. On a patient-by-patient basis, the sensitivity, specificity and accuracy of MRI for the diagnosis of sentinel node metastases were 100, 96 and 97 per cent; respective values for CT-LG were 79, 56 and 62 per cent. The specificity and accuracy of MRI were superior to those of CT-LG (P < 0·001 and P = 0·002 respectively).

CONCLUSION

SPIO-enhanced MRI at 3 T is useful for accurate diagnosis of metastatic sentinel nodes, indicating that sentinel node biopsy may be avoided in patients with breast cancer who have non-metastatic sentinel nodes on imaging.

Role of imaging in testicular cancer: current and future practice

The article provides a summary of the epidemiologic and clinical aspects of testicular malignancy. Current standard imaging and novel techniques are reviewed. Present data and clinical treatment trends have favored surveillance protocols over adjuvant radiation or chemotherapy for low-stage testicular malignancy. This has resulted in increasing numbers of imaging studies and the potential for increased long-term exposure risks. Understanding imaging associated risks as well as strategies to minimize these risks is of increasing importance. The development, validation and incorporation of alternative lower risk highly efficacious and cost-effective imaging techniques is essential.

Molecular magnetic resonance imaging of brain-immune interactions

Although the blood-brain barrier (BBB) was thought to protect the brain from the effects of the immune system, immune cells can nevertheless migrate from the blood to the brain, either as a cause or as a consequence of central nervous system (CNS) diseases, thus contributing to their evolution and outcome. Accordingly, as the interface between the CNS and the peripheral immune system, the BBB is critical during neuroinflammatory processes. In particular, endothelial cells are involved in the brain response to systemic or local inflammatory stimuli by regulating the cellular movement between the circulation and the brain parenchyma. While neuropathological conditions differ in etiology and in the way in which the inflammatory response is mounted and resolved, cellular mechanisms of neuroinflammation are probably similar. Accordingly, neuroinflammation is a hallmark and a decisive player of many CNS diseases. Thus, molecular magnetic resonance imaging (MRI) of inflammatory processes is a central theme of research in several neurological disorders focusing on a set of molecules expressed by endothelial cells, such as adhesion molecules (VCAM-1, ICAM-1, P-selectin, E-selectin, …), which emerge as therapeutic targets and biomarkers for neurological diseases. In this review, we will present the most recent advances in the field of preclinical molecular MRI. Moreover, we will discuss the possible translation of molecular MRI to the clinical setting with a particular emphasis on myeloperoxidase imaging, autologous cell tracking, and targeted iron oxide particles (USPIO, MPIO).

Layered gadolinium-based nanoparticle as a novel delivery platform for microRNA therapeutics

Specific expression patterns of microRNA (miRNA) molecules have been linked to cancer initiation, progression, and metastasis. The accumulating evidence for the role of oncogenic or tumor-suppressing miRNAs identified the need for nano-scaled platform that can help deliver nucleotides to modulate miRNAs. Here we report the synthesis of novel layered gadolinium hydroxychloride (LGdH) nanoparticles, a member of the layered double hydroxide (LDH) family, with physiochemical properties suitable for cell uptake and tracing via magnetic resonance (MR) imaging. As a proof of concept, we demonstrate the inhibition of mature miRNA-10b in metastatic breast cancer cell line using LGdH nanoparticle as a delivery platform. Through characterization analysis, we show that nanoparticles are easily and stably loaded with anti-miRNA oligonucleotides (AMO) and efficiently penetrate cell membranes. We demonstrate that AMOs delivered by LGdH nanoparticles remain functional by inducing changes in the expression of its downstream effector and by curbing the invasive properties. Furthermore, we demonstrate the traceability of LGdH nanoparticles via T1 weighted MR imaging. LGdH nanoparticles, which are biocompatible with cells in vitro, provide a promising multifunctional platform for microRNA therapeutics through their diagnostic, imaging, and therapeutic potentials.